Middle/Senior Manual QA Engineer with Mandarin Chinese

We are looking for a Middle / Senior Manual QA Engineer - IoT / Mandarin Chinese to validate an IoT ecosystem across physical devices, embedded firmware, communication protocols, backend services, and web/mobile applications. The role combines end-to-end quality ownership with onsite work at the client campus and communication with the China-based firmware team.

• Perform hands-on functional and integration testing of physical IoT devices;
• Validate end-to-end workflows from device and firmware through protocols, backend APIs, and web/mobile UI;
• Install, configure, maintain, and troubleshoot devices and test environments at the client campus;
• Test MQTT, ProtoBuf, Modbus, RS485, network connectivity, firmware upgrades, and recovery scenarios;
• Investigate defects across hardware, firmware, network, backend, protocol, and UI layers;
• Clarify technical information between Mandarin- and English-speaking engineering teams.

Requirements:

• Fluent or native Mandarin Chinese and professional working English;
• Strong Manual QA experience with complex software and hardware systems;
• Hands-on experience testing IoT, embedded, smart-home, or building-automation solutions;
• Experience with MQTT and MQTT debugging tools such as MQTTX;
• Understanding of Protocol Buffers, Modbus, RS485, REST APIs, and backend integration testing;
• Practical TCP/IP, Ethernet, Wi-Fi, DHCP, DNS/mDNS, and connectivity-troubleshooting knowledge;
• Experience testing physical hardware and embedded firmware;
• Ability to reproduce complex issues, collect logs, and produce clear defect and test documentation.

Nice to Have:

• Experience with commercial building automation systems;
• Experience testing lighting controllers, sensors, gateways, or similar embedded devices;
• Experience with OTA or firmware-upgrade testing;
• Experience with Linux, Wireshark, serial diagnostic tools, or IoT test automation.

Working Conditions:

• Work model: Onsite;
• Overlap: PST business hours;
• Target start date: October;

Benefits:

• Vacation and sick leave;
• Official state holidays;
• Professional growth through challenging projects and company-supported skills development;
• Flexible working schedule: 8 hours per day, 40 hours per week;
• Personal Career Development Plan;
• Employee support program: Discount, Care, Heals, and Legal support;
• Paid external training, conferences, and professional certifications aligned with business goals;
• Internal workshops and seminars.

Locations:

• Kirkland, WA or Bellevue, WA, United States.